The cysts are lined by PAS-positive, mucus-secreting columnar epithelial  cells, occasionally with some endocrine, Paneth and/or goblet-like cells. Glycogen is absent.

Cell stratification, papilla or gland formation and crypt invagination may be seen.

Beneath the epithelium is a densely cellular fibrous ("ovarian-like") stroma. 

At the benign end of the spectrum of appearances the cystic spaces are lined by a single layer of mucin secreting epithelial cells. 

Borderline cases show moderate dysplasia such as papillary infolding ,cellular pseudostratification. 

Anatomy of Normal Pancreas ;Normal Islets of Langerhans ; The Apud Concept ; An approach to reporting of pancreatic specimen ; Reporting of pancreatic biopsies for the diagnosis of neoplastic lesions ; Reporting of ampullary and periampullary biopsies for the diagnosis of neoplastic lesions ;Reporting of Pancreatico duodenectomy (Whipple's operation) specimen ; Reporting of Distal Pancreatectomy Specimen ; Developmental Defects of Pancreas ; Nesidioblastosis ; Pancreas Divisum ; Aberrant(Ectopic) Pancreas ; Annular Pancreas ; Pancreatic Agenesis ; Non-Neoplastic Pancreatic Cysts  ; Pancreatitis ; Acute Pancreatitis ; Chronic Pancreatitis ; Autoimmune Pancreatitis ; Herpes Simplex Pancreatitis ; Diabetes Mellitus ; Neoplasms of the Endocrine Tumours ; Islet Cell Tumours ; Glucagonomas  ; Insulinomas  ; Somatostatinoma ; VIPomas ; Pancreatic Polypeptide-Secreting Tumours ; Enterochromaffin Cell (Carcinoid) Tumours ; Pancreatic Gastrinoma ; Corticotropinoma ; Multiple Endocrine Neoplasia (MEN) Syndrome ; Carcinoma of the Pancreas ;Exocrine Pancreatic Tumours and Tumour -Like Lesions ; Paediatric Pancreatic Tumours ;Ductal Adenocarcinoma ;Acinar cell carcinoma ; Pancreatoblastoma .